An Integrative Systematic Revision and Biogeography of Rhynchocalamus Snakes (Reptilia, Colubridae) with a Description of a New Species from Israel
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An integrative systematic revision and biogeography of Rhynchocalamus snakes (Reptilia, Colubridae) with a description of a new species from Israel Karin Tamar1,2, Jiří Šmíd3, Bayram Göcmen¸ 4, Shai Meiri1,2 and Salvador Carranza5 1 The Steinhardt Museum of Natural History, Israel National Center for Biodiversity Studies, Tel Aviv University, Tel Aviv, Israel 2 Department of Zoology, Tel Aviv University, Tel Aviv, Israel 3 South African National Biodiversity Institute, Cape Town, South Africa 4 Department of Biology, Zoology Section, Ege University, Bornova-Izmir, Turkey 5 Animal Biodiversity and Evolution, Institute of Evolutionary Biology (CSIC-Pompeu Fabra University), Barcelona, Spain ABSTRACT Background. The colubrid snakes of the genus Rhynchocalamus are seldom studied and knowledge of their ecology and life history is scarce. Three species of Rhynchocalamus are currently recognized, R. satunini (from Turkey eastwards to Iran), R. arabicus (Yemen and Oman), and R. melanocephalus (from the Sinai Peninsula northwards to Turkey). All are slender, secretive, mainly nocturnal and rare fossorial snakes. This comprehensive study is the first to sample all known Rhynchocalamus species in order to review the intra-generic phylogenetic relationships and historical biogeography of the genus. Methods. We revised the systematics of Rhynchocalamus using an integrative approach and evaluated its phylogeography. The phylogenetic position within the Colubridae and the phylogenetic relationships within the genus were inferred using 29 individuals belonging to the three known species, with additional sampling of two other closely- related genera, Muhtarophis and Lytorhynchus. We analysed three mitochondrial Submitted 3 September 2016 Accepted 7 November 2016 (12S, 16S, cytb) and one nuclear (c-mos) gene fragments. Phylogenetic trees were Published 22 December 2016 reconstructed using maximum likelihood and Bayesian inference methods; the latter Corresponding author method also used to provide the first time-calibrated molecular phylogeny of the genus. Karin Tamar, [email protected] We generated a nuclear network and carried out a topology test and species delimitation Academic editor analysis. Morphological comparisons were used to differentiate among species and to Tomas Hrbek describe a new species from Israel. The studied material was comprised of 108 alcohol- Additional Information and preserved specimens, 15 photographs, and data from the literature for the examination Declarations can be found on of 17 mensural, 14 meristic, and two categorical characters. page 28 Results. The molecular results support Rhynchocalamus as monophyletic, and as DOI 10.7717/peerj.2769 having split from its sister genus Lytorhynchus during the Late Oligocene. The three recognized species of Rhynchocalamus comprise four independently evolving groups. Copyright 2016 Tamar et al. The molecular results reveal that the genus began to diverge during the Middle Miocene. We revealed that the best-studied species, R. melanocephalus, is paraphyletic. Distributed under A population, formally ascribed to this species, from the Negev Mountain area in Creative Commons CC-BY 4.0 southern Israel is phylogenetically closer to R. arabicus from Oman than to the northern OPEN ACCESS How to cite this article Tamar et al. (2016), An integrative systematic revision and biogeography of Rhynchocalamus snakes (Reptilia, Colubridae) with a description of a new species from Israel. PeerJ 4:e2769; DOI 10.7717/peerj.2769 populations of the species from Israel, Syria and Turkey. Herein we describe this population as a new species: Rhynchocalamus dayanae sp. nov. Discussion. We identify four species within Rhynchocalamus: R. satunini, R. arabicus, R. melanocephalus, and R. dayanae sp. nov., the latter, to the best of our knowledge, is endemic to southern Israel. The onset of Rhynchocalamus diversification is very old and estimated to have occurred during the Middle Miocene, possibly originating in the Levant region. Radiation probably resulted from vicariance and dispersal events caused by continuous geological instability, sea-level fluctuations and climatic changes within the Levant region. Subjects Biodiversity, Biogeography, Evolutionary Studies, Taxonomy, Zoology Keywords Diversification, Arabia, Evolution, Taxonomy, Phylogeny, Phylogeography, Middle east, Reptiles INTRODUCTION Taxonomy today often relies on molecular data for further support and information. Such data are usually preferred over morphology for the reconstruction of evolutionary relationships among organisms (Hebert et al., 2003; Tautz et al., 2003; Blaxter, 2004; Vogler & Monaghan, 2007; Padial et al., 2010). The increasing use and availability of molecular data has led to the development of new methods to study systematics (Sites & Marshall, 2003), and has proven to be an invaluable tool for evaluating the evolutionary relationships between both closely and distantly related species. Recent studies of Middle Eastern snakes have used molecular data to elucidate the inter- and intra-specific relationships among taxa, revealing high levels of genetic differentiation and cryptic diversity that do not accord with the current taxonomy. Such studies have also provided insights into the historical biogeography of the taxa and the processes that triggered their diversification (e.g., Lenk et al., 2001; Utiger et al., 2002; Nagy et al., 2003; Nagy et al., 2004; Pook et al., 2009; Stümpel & Joger, 2009; Kornilios et al., 2013). However, the biodiversity of snakes in the Middle East remains unclear, as systematic and biogeographic data for several genera are still lacking. One such example is that of the colubrid genus Rhynchocalamus Günther, 1864. Rhynchocalamus snakes are secretive, non-venomous and occasionally found near human habitations. They are poorly known and information regarding their natural history is scarce. These are small-sized, slender, fossorial aglyphous snakes that are mostly nocturnal but can also be found active during the day (Gasperetti, 1988; Disi et al., 2001; Baha El Din, 1994; Baha El Din, 2006; Avci et al., 2007; Avci et al., 2008). Morphologically they are characterized by a thin cylindrical body and short tail, small head indistinct from the neck, an enlarged rostral shield wedged between the internasals scales, and divided anal plate and subcaudal scales (Gasperetti, 1988; Disi et al., 2001; Baha El Din, 2006). Rhynchocalamus snakes prefer humid areas with little vegetation and are found in mountainous areas in both Mediterranean and Irano-Turanian ecozones (Fig. 1), on heavy soils but not on sand. In southern Israel, Jordan, and Egypt (i.e., the Sinai Peninsula), they Tamar et al. (2016), PeerJ, DOI 10.7717/peerj.2769 2/37.